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Unread 05-02-2010, 11:49
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Re: Bungy and Surgical tubing

Quote:
Originally Posted by Bruceb View Post
O.K. I have to interject here. Again as it seems noone read my previous post. Our primary sponsor is the local Bimba sales source. The sales guy is one of our mentors so I posed the question to him about the pistons hitting the end stop. He talked to his contact at bimba and they said that something like a few thousand hits will probably not damage the cylinder but if you are realy concerned just order a cylinder with an air cushion at the end in question and there will be no problems. That is what we did. We are using a 1.5 inch by 8 inch stroke piston precharged at 3 inches to 60 psi powering a speed increasing lever kicker that is augmented with a bunch of wraps of surgical tubing. When this fires I don't know the speed but you don't want your hand in the way. We get up to 35 ft of in the air kick on the ball. When the cylinder hits the adjustable air cushion on the end there is NO CLINK and you can see it bounce and then slowly settle to the end. Very cool. SOOO, I am for hard external stops only if you do not have an internally cushioned cylinder.
Bruce
No one is ignoring your post (well at least I'm not), but the free cylinders from Bimba do not come with air cushions. Teams will not pay $125, or more, for a cylinder they can get for free just to get an air cushion. Additionally, air cushions add weight (~.25-.50 LB) and size (~.375 -.50") to the cylinder.

If teams can afford air cushions in their cylinders then by all means use them (and bring the specification sheets to assure the inspectors that it is safe), and if you cannot then use a hard stop.
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